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Howzat? Spin bowlers looking to gain the upper hand in the next upcoming Ashes cricket series between Australia and England, might find inspiration from a new study.

Dr Garry Robinson of the Australian Defence Force Academy at the University of New South Wales and Emeritus Professor Ian Robinson of University of Melbourne have developed a set of equations that they believe explain the trajectory of a spinning ball as it moves through the air.

The research, which appears today in the journal Physica Scripta, claims the presence of a cross-wind from either side of the cricket pitch can cause the spinning ball to either "hold up" or "dip", depending on which direction the wind is coming from.

They also looked at the effect of speed, gravity, air resistance and the Magnus or 'lift' force. The Magnus force is a commonly observed effect in ball sports, in which the spin of a ball causes it to curve away from its trajectory -- a la 'bend it like Beckham'.

"The effects... are probably very well known to class spin bowlers, so we are not attempting to tell them what they already know," they write.

"However, the paper has served to quantify the effects and provide a means of treating other combinations of spin and winds."

For example, the researchers calculated that a crosswind of 14 kilometres per hour is enough to cause a spinning cricket ball to hit the ground 14 centimetres from where it would have landed without wind. That would be enough to fool batsmen into playing the wrong shot.

The research also found that a spinning cricket ball tends to drift in the latter stages of its flight as it descends; an effect that is well-known and used by spin bowlers.

"We hope that this work can be used to cast new light on the motion of a spinning spherical object particularly as applied to cricket," says Garry Robinson.

But their research, which was motivated out of an "interest in physics and a long love of sport of all sorts" also applies to other ball sports such as golf, they say.

Last year, researchers from the United Kingdom and New Zealand found changes in humidity didn't cause a cricket ball to swing in mid-air, an effect often seen during games staged in England.

They found that while altitude and the condition of a cricket ball increased swing, no link was found between moisture levels and sideways movement.

The researchers instead found that stable air, typical during overcast weather, provided the ideal environment for swing bowling.